Several types of holders are already known to provide work panels upon which puzzle pieces can be assembled and to provide means for constraining such pieces in predetermined positions for storage before completion of the puzzle. These holders are useful since it very often occurs that a puzzle cannot be completely assembled without interruption and in fact, work on a single puzzle, may extend over periods of several days or weeks. Since the pieces of a partially assembled puzzle cannot be disturbed throughout these periods, it is generally the practice to let the puzzle occupy a table or other work surface supporting the same until it is completed, this can create inconvenience.
U.S. Pat. No. 4,484,745 dated Nov. 27, 1984 and entitled JIG-SAW PUZZLE ASSEMBLY AND STORAGE APPARATUS, inventor John R. SLEEPER describes a work panel on which the puzzle pieces are assembled. This panel is made of wood or plastic and covered by a thin layer of tin or steel constituting a ferromagnetic base. A flexible magnetic cover sheet is hinged to one edge of the work panel and adheres to the thin layer of tin or steel all around the puzzle pieces to hold them in a desired relationship and against shifting during horizontal or vertical storage of the panel. The work panel of this holder is in the form of a table top and is provided with foldable legs. This holder, when made of a size to accommodate puzzles containing a great number of pieces, is too big to be conveniently carried, so much so because the required size must be larger than that of the assembled puzzle to provide extra room to lay out individual pieces to be assembled.